diff --git a/nixos/modules/common.nix b/nixos/modules/common.nix
index fdb2af1..fc58eb7 100644
--- a/nixos/modules/common.nix
+++ b/nixos/modules/common.nix
@@ -52,6 +52,10 @@ in
           trusted-users = [ "@wheel" ];
           experimental-features = [ "nix-command" "flakes" "ca-derivations" ];
         };
+        gc = {
+          options = mkDefault "--max-freed $((8 * 1024**3))";
+          automatic = mkDefault true;
+        };
       };
       nixpkgs = {
         overlays = [